The Mind of an Assassin
by starsofimagination
Summary: Mary was about to kill Charles Augustus Magnussen, but she was interrupted. Set during His Last Vow. Spoilers!
1. Chapter 1

_AN: So I might do a follow up of this, I'm not sure yet. I'm really interested in knowing what Mary was thinking and what was going through her mind during all this, so naturally, that led to this. Tah dah, enjoy!_

She had the gun pointed squarely at him. Her breath was calm and steady whereas her hostage...not so much.

"I've been waiting a long time for this," Mary said, circling the man on his knees. "Do you know how long it took me to plan this?"

"A very long time, I imagine," Charles Augustus Magnussen answered as calmly as he could. "You knew I had information on you. You had to befriend Janine and become close to her, enough so that she was your maid of honor-"

"Shut up," Mary hissed. "You're just buying yourself time. I didn't come here to chat with you."

"Then what are you going to do to me Mary?"

"I came for my files. You're going to give me everything you have on me, and then I'm going to kill you," she said softly and slowly. She looked him over. The man that no one stood up to was now at her mercy. She stopped circling him and stood in front of him.

"What will your child think of this?" Charles asked, looking up at her.

Mary pressed the gun right against his left temple. "How did you know I was pregnant?"

Charles chuckled. "I know everything, but you didn't answer my question? What will your child think of this? What will your husband think of this?"

"Do not speak to me about them. I'm doing this for them. There is nothing I wouldn't do to protect John and our child."

At that moment, Charles began to beg. "What would your husband think? Your lovely husband? Surely what would he say to you now?"

Mary shut him out. She cocked the gun and pointed it at his forehead. If he wasn't going to give her the files, she would just kill him and get them herself. She looked down at Magnussen. His mouth was still moving but no words came out. She couldn't hear him. She was too focused.

"Additionally if you're going to commit murder, you might consider changing your perfume, Lady Smallwood," came a voice from behind Mary, bringing her out of her focus.

Mary froze. She knew that voice. It couldn't be. No. This couldn't be happening now.

"Sorry, who?" Charles asked, lowering his hands and looking past Mary. "That's...not Lady Smallwood, Mr. Holmes."

She was right. It was him. Mary turned around, her gun pointed right at Sherlock. She could see the look of shock flash through his eyes in the darkened room. She suddenly felt scared. If Sherlock were here, that meant John couldn't be too far behind. John couldn't know. He must never find out about what she really was, and now, Sherlock was going to mess that all up. Damn him!

"Is John with you?" Mary asked softly.

"He's um-" Sherlock stammered.

"Is John here?" She asked again, growing impatient.

"H-He's downstairs," Sherlock answered, his eyes fixed on her.

"So, what do you do now?" Charles slowly asked. "Kill us both?"

"Mary, whatever he's got on you, let me help," Sherlock said firmly.

For a brief moment, Mary considered it, but then quickly dismissed it. Sherlock couldn't help her because then John would find out. No, she had to do this on her own. It was the only way to protect John.

"Oh Sherlock, if you take one more step I swear I will kill you," Mary threatened. She hoped that would be enough to stop him and buy herself some time.

"No, Mrs. Watson, you won't," Sherlock said, almost smugly.

Mary let out a small inaudible gasp as he began to step forward. She couldn't kill him. If she killed him and Magnussen. If she did John would be the suspect. Plus she didn't want to kill Sherlock. Sherlock was her friend. He was her husband's best friend. She already saw what his "death" did to him once. She couldn't see John go through that again. No, she had to incapacitate him. That would buy her time.

She quickly aimed and shot Sherlock on the right side of his chest. Sherlock looked down at his chest as blood started to seep through his white shirt.

"I'm sorry Sherlock, truly am," Mary said, her voice cracking every so slightly.

"Mary…" Sherlock said, his voice filled with betrayal.

Mary turned the gun away from Sherlock and back to Magnussen, her eyes still fixed on Sherlock. It was like watching him in slow motion. She watched as he fell to the ground. As soon as he was on the ground she turned and pistol whipped Magnussen hard, knocking him out cold. Grabbing her phone, she dialed 999 for an ambulance.

"You're not going to die Sherlock, not here, and not like this," She whispered more to herself. She gave him one last look and quickly left to avoid John finding her. She had much more work to do now.


	2. Chapter 2

A/N: So I decided I would continue this after all. Enjoy!

"You don't tell him," Mary told a half conscious Sherlock. She gazed down at him, feeling nothing but guilt. "You don't tell John." She moved to sit on the bed. "Sherlock," she said in a sing-song voice. "Look at me and tell me you won't tell him."

Mary watched Sherlock turn his head slightly and look at her. His eyes slowly closed and he fell back into unconsciousness. Mary sighed. It was no use of frowned and left the hospital room to join John in the hallway.

"Ready?" John asked. "What did you want to say to him anyways?"

"Oh nothing. Just sort of chastised him for getting shot," Mary teased, trying to lighten the mood before pausing. "I think he's going to be okay," she added hopefully.

"I hope so," John sighed. She could see the fear and restlessness in his eyes. "I can't wait to find the bastard who shot him. I'll kill him myself."

"I know." Mary turned away and frowned. John was going to hate her if he found out. "Let's get home. You look exhausted."

"I feel exhausted. I've been up all night with Sherlock." John took her hand and began to lead her out of the hospital. "Let's get some Thai food on the way home."

"Sounds good. I don't feel like cooking tonight." Mary smiled. She was going to at least try and enjoy what precious moments she had left with John.

XXXXX

"That was delicious," John groaned tossing away his Thai food containers into the trash bin. "That's just what I needed."

Mary laughed. "I'm glad," she responded. She kissed his cheek. "I'm going to get a shower and get ready for bed. It's been a long day. You should try and get some sleep."

"I'll be up soon," John softly said.

Mary nodded and went up to the bathroom. She must have been in the shower for at least forty-five minutes. Her mind just wouldn't stop thinking about everything that had happened. She thought about every possible outcome, everything that she could have done differently, how John would react if Sherlock told him. Not _if_, but when because she knew Sherlock would tell him. That still wasn't going to stop her from trying to bargain for his silence.

Then of course there was the baby. She placed a hand on her stomach. In a few months time she would have a baby bump. Mary sighed. Already she was screwing up the life of the child growing inside of her. She had no doubt that John would love the child and would always be there for him or her, but she didn't want her child growing up to resent her. She didn't want her child to know about her past, and if worst came to worst and she ended up in prison, she didn't want to miss out on watching her child grow up. She was stressed out, but she didn't let it show. Years of training allowed her to keep her cool under stressful times.

When she finally stepped out of the shower, she dried her hair and walked into the bedroom with nothing but a towel wrapped around her. The bedroom was dark and she could make out a figure laying in bed. It looked as though John took her advice and went to bed. She was about to pull out a pair of panties and her pajamas from a drawer when John sat up in bed.

"Come here," he said softly.

"What is it?" Mary asked curiously standing straight up with the towel still wrapped around her.

"Just come here." He patted to the spot on the bed next to him.

Mary did as he asked and sat down on the bed. Before she could say anything John turned and kissed her passionately. Mary kissed back with equal passion as John's arms snaked around her and pulled her close.

"I need you tonight," John whispered against her lips when the kiss broke.

"I'm here," Mary replied, cupping his cheek with a hand and kissing John again.

John undid the towel that was wrapped around Mary and tossed it aside. He kissed down Mary's neck slowly. She let out a soft moan and tilted her neck to give John better access. She let him lay her back on the bed and kiss down her body. He was always gentle with her, and she loved it. He began to caress and kiss her breasts before going on to worship every part of her body.

John then sat up and pulled off his own clothes before Mary brought John's lips back to her own. As she kissed him, she used her strength and rolled them over so she was now straddling him. "Let me make you feel good," she said softly as she peppered kisses down his neck. She really did want to make him feel good. After all, it was her fault he was feeling the way he was. It was her fault that his best friend nearly died.

"Please," John moaned, bringing Mary out of her thoughts. She could feel his erection against her. She shifted and kissed down his chest slowly and then back up to his lips. As she kissed him, he adjusted her hips and lined her up with his cock before slowly pushing into her. Mary moaned into John's mouth and broke the kiss to stare down into his lust filled eyes. In that moment, all worries, fears, and cares seemed to disappear. She loved him more than anything in the world and nothing else mattered.

John began to thrust into her, making her moan softly. He gripped her hips, lifting her gently as he moved. Mary leaned down and kissed and nipped at John's neck as he sped up the pace. He moaned loudly as he thrust into her, and she loved the sounds he made. It turned her on even more. Swiftly, he flipped her over so he was on top of her.

They continued to move together, their moans and whimpers filling the small bedroom. Soon John's thrusts soon became erratic as he began chanting her name. Mary's fingers dug into John's skin, gripping him tight as she reached her peak. They both called out each others' name as the climaxed together. John pulled out of her and laid down next to Mary, pulling her in his arms.

"I love you. I love you so much," John whispered, peppering her neck with kisses.

"I love you too. Always," Mary responded, her guilt now returning. She let John hold her as he fell into a peaceful sleep. "I'm sorry," she whispered. "I'm so sorry. I hope you don't completely hate me."

Soon after, Mary followed her husband into sleep.


End file.
